DE102006048542A1 - Systems, methods and devices for fine-sensing modules - Google Patents

Systems, methods and devices for fine-sensing modules

Info

Publication number
DE102006048542A1
DE102006048542A1 DE102006048542A DE102006048542A DE102006048542A1 DE 102006048542 A1 DE102006048542 A1 DE 102006048542A1 DE 102006048542 A DE102006048542 A DE 102006048542A DE 102006048542 A DE102006048542 A DE 102006048542A DE 102006048542 A1 DE102006048542 A1 DE 102006048542A1
Authority
DE
Germany
Prior art keywords
input signal
signal
rf input
correlation
characterized
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
DE102006048542A
Other languages
German (de)
Inventor
Hak Sun Kim
Chang Ho Lee
Jung Suk Paju Lee
Wang Myong Woo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Samsung Electro Mechanics Co Ltd
Original Assignee
Samsung Electro Mechanics Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US72903405P priority Critical
Priority to US60/729,034 priority
Priority to US11/458,280 priority
Priority to US11/458,280 priority patent/US20070092045A1/en
Application filed by Samsung Electro Mechanics Co Ltd filed Critical Samsung Electro Mechanics Co Ltd
Publication of DE102006048542A1 publication Critical patent/DE102006048542A1/en
Application status is Ceased legal-status Critical

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00Modulated-carrier systems
    • H04L27/0012Modulated-carrier systems arrangements for identifying the type of modulation
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40Circuits
    • H04B1/403Circuits using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency
    • H04B1/406Circuits using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency with more than one transmission mode, e.g. analog and digital modes

Abstract

Systems, methods and apparatus for fine-sensing modules are proposed which serve to identify one or more types of signals from a radio frequency (RF) input signal. The fine-sensing modules may include a multiplier that combines an RF input signal and a delayed RF input signal to produce a correlation signal and an integrator that receives the correlation signal from the multiplier, wherein the integrator determines correlation values by integrating the correlation signal. The fine-sensing module further includes a comparator in conjunction with the integrator which compares the correlation values to one or more thresholds to generate information indicative of at least one signal characteristic of the RF input signal.

Description

  • For this Registration becomes the priority U.S. Provisional Application No. 60 / 729,034, filed on October 21, 2005, entitled "Systems, Methods and Apparatuses for Fine-Sensing Modules, which are hereby incorporated by reference Completely is included. Furthermore, the application with the following, simultaneously pending United States applications, each of which is incorporated herein by reference in its entirety are: "Systems, Methods and Apparatuses for Spectrum-Sensing Cognitive Radios ", filed on 18. July 2006, Serial Number US 11 / 458,249, and "Systems, Methods and Apparatuses for Coarse-Sensing Modules, filed July 18, 2006 with the File number US 11 / 458,275.
  • AREA OF INVENTION
  • The The present invention generally relates to wireless communication, and in particular, systems, methods and devices for identifying one or more types of signals from a radio frequency (RF) input signal.
  • BACKGROUND THE INVENTION
  • In the United States and a number of other countries Often the use of the radio spectrum by an approval authority like regulated and assigned by the FCC (Federal Communications Commission), to the communication needs of instances such as Companies and local and state authorities as well as individuals too fulfill. More specifically, the FCC licenses a number of segments of the spectrum to entities or individuals ("licensee") for commercial or public Use. These licensees can an exclusive one Right to use their respective licensed segment of the spectrum for one certain geographical area or a certain period of time to have. Such licensed segments of the spectrum are considered necessary considered to prevent interference from other sources or mitigate. However, if certain segments of the spectrum are at a particular location or should not be used at any given time ("the available spectrum") should others Devices should be able to have such an available spectrum for communication to use. Such use of the available spectrum would be a more efficient use of the radio spectrum or ranges thereof Offer.
  • before disclosed spectrum sensing techniques to determine the available Spectrum has been met with resistance for at least two reasons: (1) They do not work for you sophisticated signal formats, or (2) excessive hardware performance and / or excessive power consumption for the Calculation required. For example, a spectrum-sensing technique has been used disclosed in which a non-coherent Energy detector a calculation of a Fast Fourier transformation (FFT) for a narrowband input signal performs. The FFT provides the spectral components of the narrowband input signal, which are then compared to a predetermined threshold level to detect significant signal reception. however This predetermined threshold level is largely passed through unknown and changeable Noise level affected. Furthermore, the energy detector distinguishes not between modulated signals, noise and interference signals. Thus, he does not work for sophisticated signal formats, such as a splayed Spectral signal, frequency hopping and multi-carrier modulation.
  • When Another example has been a cyclostationary feature detection technique as a spectrum-sensing technique discloses which cyclic features of modulated signals, sinusoidal carriers, periodic Pulse trains, uses repetitive jump patterns, cyclic prefixes and the like. correlation functions for the Spectrum are calculated to be unique to the signal Features such as modulation types, symbol rates and presence of interference causers to detect. Because the detection span and the frequency resolution Compromises are an upgrade Of the digital system, the only way to detect the detection resolution for the broadband input signal spectrum to improve. However, such upgrading requires the digital system excessive hardware services and power consumption for the calculation. Furthermore, flexible or scalable detection resolution is not without hardware changes possible.
  • Accordingly There is a need in the industry for fine sensing modules for identifying one or more types of signals from a radio frequency (RF) input signal, minimizing hardware and power consumption requirements become.
  • SUMMARY THE INVENTION
  • According to one embodiment The present invention is a fine-sensing module provided, which serves one or more types of signals from a Radio frequency (RF) input signal. For example can the fine-sensing modules the allocation of a spectrum in connection with communication over a Variety more common and emerging wireless standards including IS-95, WCDMA, EDGE, GSM, Wi-Fi, Wi-MAX, Zigbee, Bluetooth, digital TV (ATSC, DVB) and similar detect.
  • The Fine-sensing modules can as part of cognitive radios personified although in other embodiments the fine-sensing modules used in other wireless devices and systems can. As described here, can the fine-sensing modules an analog auto-correlation function (AAC = Analog Auto Correlation), which implements the degree of agreement (i.e., the correlation) between two signals, though other alternatives can also be used.
  • According to one embodiment The present invention is a radio frequency (RF) spectrum sensing system intended. The system has a multiplier which is an RF input signal and a delayed one RF input signal linked to to generate a correlation signal, and an integrator, the receives the correlation signal from the multiplier, wherein the integrator by integrating the correlation signal correlation values certainly. The system further communicates a comparator with the integrator having the correlation values with at least a threshold to produce information that indicate at least one signal feature of the RF input signal.
  • According to one The subject of the present invention is the at least one signal feature Modulation type and / or frame structure of the RF input signal. According to one Another object of the present invention, a delay of the delayed RF input signal reconfigurable. According to another object According to the present invention, the integrator may include an integrator be sliding window. According to one Still another object of the present invention, the system continue an analog-to-digital converter to digitize the correlation values. According to one Another object of the present invention may be a value for a or more of the thresholds may be reconfigurable. According to one Still another object of the present invention, the multiplier the correlation signal by multiplying the RF input signal with the delayed Generate RF input signal.
  • According to one another embodiment The present invention is a method for identifying the use of a radio frequency (RF) spectrum provided. The Method includes receiving an RF input signal, delaying the RF input signal to a delayed Generate RF input signal, and linking the RF input signal with the delayed RF input signal, to generate a correlation signal on. The method points further calculating correlation values by integrating the correlation signal and comparing the correlation values with at least one threshold to generate information based on at least one signal feature indicate the RF input signal.
  • According to one The subject matter of the present invention may be to compare the correlation values comparing the correlation values with at least one threshold to generate information, the modulation type and / or Display the frame structure of the RF input signal. According to one Another object of the present invention, the method further reconfiguring a delay in connection with the delayed RF input signal exhibit. According to one Still another object of the present invention may be calculating of the correlation values, calculating the correlation values Apply a sliding-window integrator to the correlation signal exhibit. According to one Another object of the present invention, the method further digitizing the information that at least indicates a signal characteristic of the RF input signal. According to one Yet another object of the present invention, the method further reconfiguring a value for at least one threshold exhibit. According to one Still another object of the present invention, the linking of the RF input signal and the delayed RF input signal multiplying the RF input signal with the delayed one Have RF input signal.
  • In accordance with yet another embodiment of the present invention, a high frequency (RF) spectrum sensing device is provided. The apparatus includes an antenna for receiving an RF input signal, a delay module delaying the RF input signal to produce a delayed RF input signal, and a multiplier for combining the RF input signal with the delayed RF input signal to obtain a correlation signal to generate. The device further has an inte grator integrating the correlation signal to calculate correlation values and a comparator comparing the correlation values to at least one threshold to generate information indicative of at least one signal characteristic of the input radio signal.
  • According to one The object of the present invention is the delay of the delay module be reconfigurable. According to one Another object of the present invention, the integrator Be an integrator with a sliding window. According to another object The present invention may provide a value for at least one threshold be reconfigurable. According to one Another object of the present invention, the at least a signal feature the modulation type and / or the frame structure of the RF input signal exhibit. According to one Still another object of the present invention, the multiplier serve the RF input signal with the delayed Multiply RF input signal.
  • SHORT DESCRIPTION THE DRAWINGS
  • After this the invention has been described in general, reference will now be made on the attached Drawings, which are not necessarily to scale and in which:
  • 1 FIG. 4 illustrates a functional block diagram of an exemplary cognitive radio system according to one embodiment of the invention. FIG.
  • 2 an exemplary flowchart of the cognitive radio system 1 represents.
  • 3 represents a compromise between a wavelet pulse width and a wavelet pulse frequency in accordance with an embodiment of the present invention.
  • 4A FIG. 3 illustrates a block diagram of an exemplary MRSS (Multi-Resolution Spectrum Sensing) implementation according to one embodiment of the present invention.
  • 4B an example of a scalable resolution control according to an embodiment of the present invention.
  • 5A represents a waveform of a double tone signal and 5B represents the corresponding spectrum to be detected with the MRSS implementation according to one embodiment of the present invention.
  • 6 FIG. 4 illustrates a waveform of the wavelet pulse train in accordance with an embodiment of the present invention. FIG.
  • 7A represents the I component of the waveform of the sinusoidal IQ carrier and 7B represents the Q component of the waveform of the sinusoidal IQ carrier according to an embodiment of the present invention.
  • 8A represents modulated wavelet pulses obtained from a wavelet generator with an I component of a sinusoidal IQ carrier in accordance with an embodiment of the present invention.
  • 8B represents modulated wavelet pulses obtained from a wavelet generator with a Q component of a sinusoidal IQ carrier in accordance with an embodiment of the present invention.
  • 9A represents a correlation output signal waveform for the input signal with the I component of a sinusoidal IQ carrier according to an embodiment of the present invention.
  • 9B represents a correlation output signal waveform for the input signal with the Q component of a sinusoidal IQ carrier according to an embodiment of the present invention.
  • 10A represents values sampled by the integrator and the analog-to-digital converter for the correlation values with the I-component of the wavelet waveform at given intervals according to an embodiment of the present invention.
  • 10B represents values sampled by the integrator and the analog-to-digital converter for the correlation values with the Q component of the wavelet waveform at given intervals according to an embodiment of the present invention.
  • 11 represents an exemplary form of the spectrum detected by the spectrum recognition module in the MAC module according to an embodiment of the present invention.
  • 12 - 17 Represent simulations of various signal formats detected by MRSS implementations according to embodiments of the present invention.
  • 18 FIG. 10 is an exemplary circuit diagram of the coarse sensing module according to one embodiment of the present invention. FIG.
  • 19 FIG. 4 illustrates a functional block diagram of a fine-sensing technique using the AAC function according to an embodiment of the present invention.
  • 20A illustrates an exemplary OFDM data symbol followed by a preamble according to an embodiment of the present invention.
  • 20B represents the spectrum of an IEEE802.11a input signal to be detected with an AAC implementation according to one embodiment of the present invention.
  • 21A represents an IEEE802.11a input signal and 21B represents a delayed IEEE802.11a signal according to an embodiment of the present invention.
  • 22 represents a waveform of a correlation between the original input signal and the delayed signal according to an embodiment of the present invention.
  • 23 represents a waveform generated by an integrator according to an embodiment of the present invention.
  • 24 FIG. 4 illustrates an example configuration for a frequency agile radio front end in accordance with an embodiment of the present invention. FIG.
  • PRECISE DESCRIPTION THE FIGURES
  • The The present invention will be described below in more detail with reference to FIG on the attached Drawings in which some but not all embodiments the invention are shown. The invention can be in many different Shapes are and should not be considered as in the embodiments described herein limited be understood; rather, the embodiments are provided so that the description meets legal requirements. It will be continuous same reference numerals for similar Elements used.
  • embodiments of the present invention relate to cognitive radio systems, Methods and apparatus for exploiting limited resources of the spectrum. The cognitive radios may be an agreed and / or opportunistic sharing of the spectrum over a wide frequency range, the covering a variety of mobile communication protocols and standards, enable. According to the present Invention can embodiments of the cognitive radio be able to intelligently use a segment of the radio spectrum to detect and a temporarily unused segment of the spectrum to use quickly without the communication between other authorized Disturb users. The use of these cognitive radios can make it a lot more heterogeneous wireless networks (such as various communication protocols, Enable frequencies etc.), to coexist. These wireless networks can be cellular Wireless Networks, W-PANs (Wireless Personal Area Network), W-LANs (Wireless Local Area Network) and W-MANs (Wireless Metro Area Network). The wireless networks can also alongside television networks, including digital television networks, exist. Other types of networks may be used in accordance with the present invention as known to those of ordinary skill in the art.
  • A. Overview of the Cognitive Radio System
  • 1 FIG. 12 illustrates a functional block diagram of an exemplary cognitive radio system according to an embodiment of the present invention. In particular, FIG 1 a cognitive radio 100 represented, which is an antenna 116 , a transmit / receive switch 114 , a wireless frontend 108 , an analog broadband spectrum sensing module 102 , an analog-to-digital converter 118 , a signal processing module 126 and a MAC (Medium Access Control) module 124 having.
  • During operation of the cognitive radio system 1 , which in conjunction with the flowchart 2 may be high frequency (RF) input signals from the antenna 116 be received. In an exemplary embodiment of the present invention, the antenna 116 a broadband antenna capable of operating over a wide frequency range, from a few megahertz (MHz) to a multi-gigahertz (GHz) range. The from the antenna 116 received input signals can be sent to the analog broadband spectrum sensing module 102 via the send / receive switch 114 (Block 202 ) or otherwise delivered. The spectrum-sensing module 102 can be either a coarse-sensing module 104 or a fine-sensing module 106 or both. As can be concluded from their names, the coarse-sensing module 104 detect the existence or presence of a suspicious segment of the spectrum (e.g., potentially used segments of the spectrum), whereas the fine-sensing module 106 check or otherwise analyze the detected suspect segments of the spectrum to determine the particular types of signals and / or the modulation schemes used therein.
  • Referring again to 2 can the coarse-sensing module 104 initially the allocation of the spectrum for the received input signal (block 204 ). The information about the occupancy of the spectrum can be obtained by the analog-to-digital (A / D) converter 118 , which may be a low-speed A / D converter in an exemplary embodiment of the present invention, is converted from analog to digital. The from the A / D converter 118 Provided digital information about the occupancy of the spectrum can be obtained from the spectrum recognition module 120 in the MAC module 124 be received. The spectrum recognition module 120 can perform one or more calculations on the digital spectrum occupancy information to see if one or more segments of the spectrum are currently in use or occupied by others. The spectrum recognition module 120 may be implemented as hardware, software or a combination thereof.
  • In some cases, based on the detected segments of the spectrum, the MAC module can 124 to request a precise verification of the allocation of the spectrum (block 206 ). In such a case, the fine-sensing module 106 serve to identify the particular types of signals and / or modulation schemes used in at least a portion of the spectrum occupancy (block 208 ). The information identifying the signal types and / or modulation schemes may then be provided by the A / D converter 118 digitized and sent to the spectrum recognition module 120 to be delivered. Information about the signal type and / or the modulation scheme may be required to determine the influence of interference causers in the detected suspect segments of the spectrum.
  • According to an embodiment of the present invention, the spectrum recognition module 120 Information from the coarse-sensing module 104 and / or fine-sensing module 106 with a spectrum exploitation database (block 210 ) to determine an available (for example, unused or secure) slot in the spectrum (block 212 ). The spectrum usage database may contain information regarding known types of signals, modulation schemes, and subordinate frequencies. Likewise, the spectrum exploitation database may include one or more thresholds for determining whether information from the coarse-sensing module 104 and / or fine-sensing module 106 indicate one or more occupied spectra. According to an exemplary embodiment of the present invention, the spectrum utilization database may be updated based on information received from an external source, including periodic transmissions from a base station or other remote station, removable information stores (eg, removable chips, memory, etc.). , Internet repositories. Alternatively, the spectrum usage database may be updated based on internal techniques, such as based on adaptive learning techniques including trial and error, test arrangements, statistical calculations, etc.
  • The from the spectrum detection module 120 certain sensing results may be the control (for example, a spectrum frequency allocation module) of the MAC module 124 be reported, and permission may be requested for a particular spectrum usage (block 214 ). After approval control can be the reconfiguration block of the MAC module 124 a reconfiguration information to the radio frontend 108 via the signal processing module 126 deliver (block 218 ). In an exemplary embodiment of the present invention, the radio frontend 108 be reconfigurable to operate at different frequencies ("frequency agile"), with the particular frequency or frequencies of the selected segments of the spectrum being for use in communication through the cognitive radio 100 can depend. In conjunction with the frequency agile frontend 108 can the signal processing module 126 which, in an exemplary embodiment, may be a physical layer physical signal processing block, the performance of the cognitive radio 100 with adaptive modulation and interference mitigation technique.
  • Many modifications can be made to the cognitive radio 100 be made without departing from the embodiments of the present invention. In an alternative embodiment, the antenna 116 comprise at least two antennas. A first antenna can be used for the wireless frontend 108 whereas the second antenna for the spectrum-sensing module 102 can be provided. The use of at least two antennas may require a transmit / receive switch 114 between the wireless frontend 108 and the spectrum sensing module 102 according to an exemplary embodiment make redundant. In another embodiment according to the present invention, however, a transmit / receive switch 114 continue between the transmitter 110 and the receiver 112 the wireless frontend 108 to be required. Furthermore, the spectrum-sensing module 102 , the A / D converter 118 and the MAC module 124 remain in operation, even if the wireless frontend 108 and the signal processing module 126 not in operation or in standby. This can reduce the power consumption of the cognitive radio 100 being there, being the cognitive radio 100 is further possible to determine the occupancy of the spectrum.
  • After a general description of the cognitive radio 100 now becomes more accurate the operation of the components of the cognitive radio 100 described.
  • B. Spectrum sensing components
  • Further referring to 1 can the spectrum-sensing module 102 the coarse-sensing module 104 and a fine-sensing module 106 according to an exemplary embodiment of the present invention. However, in other embodiments of the present invention, either the spectrum sensing module may be used 102 or the coarse-sensing module 104 to be used alone as needed. Although the spectrum-sensing module 102 as a component of an exemplary cognitive radio 100 can be such a spectrum-sensing module 102 further be embodied in alternative applications in another device and used as an effective method for determining the available spectrum. These alternative applications may include Wireless Personal Area Network (W-PAN), Wireless Local Area Network (W-LAN), wireless phones, cell phones, digital TVs, and GPS systems.
  • With reference to the spectrum sensing module 102 out 1 can the spectrum-sensing module 102 the coarse-sensing module 104 and the fine-sensing module 106 which can be used together to increase the accuracy of the spectrum detection performance of the MAC module 124 to improve. Furthermore, according to an embodiment of the present invention, the spectrum sensing module 102 be implemented in an analog domain that can provide multiple features. For example, such a spectrum-sensing module implemented in the analog domain may be 102 provide fast detection of a broadband frequency range, low power consumption, and low hardware complexity requirements. The coarse-sensing module 104 as well as the fine-sensing module 106 of the spectrum sensing module 102 will now be described in more detail below.
  • 1. Coarse-sensing module
  • According to an exemplary embodiment of the present invention, the coarse-sensing module 104 in providing a multi-resolution sensing feature known as MRSS (Multi-Resolution Spectrum Sensing), use wavelet transforms. The use of MRSS with the coarse-sensing module 104 can enable flexible detection resolution without requiring an increase in hardware overhead.
  • With MRSS, a wavelet transform can be applied to a given time-varying signal to determine the correlation between the given time-variant signal and the function used as the basis (for example, a wavelet pulse) for the wavelet transform is to determine. This particular correlation may be known as a wavelet transform coefficient, which may be determined in analog form according to an embodiment of the present invention. The wavelet pulse described above, which serves as the basis for the MRSS applied wavelet transform, can be varied or configured, such as by means of the MAC module 124 , according to an embodiment of the present invention. In particular, the wavelet pulses for the wavelet transformation can be varied in bandwidth, carrier frequency and / or period. By varying the wavelet pulse width, carrier frequency and / or period, the spectral contents provided by the wavelet transform coefficient for the given signal can be represented with a scalable resolution or multi-resolution. For example, by varying the wavelet pulse width and / or carrier frequency after having been retained for a particular interval, the wavelet transform coefficient may provide an analysis of the spectral content of the time variant signal according to an exemplary embodiment of the present invention. Likewise, the shape of the wavelet pulse may be configurable according to an exemplary embodiment of the present invention.
  • a. Wavelet pulse selection
  • The selection of a suitable wavelet pulse, and in particular the width and carrier frequency of the wavelet pulse, for use in MRSS will now be described in greater detail. 3 represents the compromise between the wavelet pulse width (Wt) 302 and the wavelet pulse rate (Wf) 304 (also referred to herein as "resolution bandwidth", for example) which may be taken into account when choosing an appropriate wavelet pulse. In other words, with an increase in the wavelet pulse width 302 In general, the wavelet pulse rate decreases 304 , As in 3 can represent the wavelet pulse width 302 inversely proportional to the wavelet pulse rate 304 be.
  • According to one embodiment of the present invention, uncertainty inequality can be limited to a choice of wavelet pulse width (Wt). 302 and resolution bandwidth (Wf) 304 be applied. In general, the uncertainty inequality offers limits for the wavelet pulse width (Wt). 302 and resolution bandwidth (Wf) 304 for certain types of wavelet pulses. An uncertainty inequality can be used if the product of wavelet pulse width (Wt) 302 and resolution bandwidth (Wf) 304 is greater than or equal to 0.5 (ie Wt * Wf ≥ 0.5). Equality can be achieved if the wavelet pulse is a Gaussian wavelet pulse. Thus, for a Gaussian wavelet pulse, the wavelet pulse width (Wt) 302 and resolution bandwidth (Wf) 304 for use in the wavelet transformation are chosen so that their product is equal to 0.5 according to the uncertainty inequality.
  • Even though for one illustrative embodiment Gauss Wavelet pulses can be described as other forms of wavelet pulses can be used, including from the wavelet families Hanning, Haar, Daubechies, Symlets, Coiflets, Biorthogonal (Bior) Splines, Reverse Biorthogonal (Bior), Meyer, DMeyer, Mexican Hat, Morlet, Gauss complex, Shannon, Frequency B-spline and Morlet complex.
  • b. Block diagram for MRSS implementation
  • 4A FIG. 4 illustrates a block diagram of an exemplary MRSS (Multi-Resolution Spectrum Sensing) implementation that includes a coarse-sensing module 104 having. In particular, the coarse-sensing module can receive a time-varying RF input signal x (t) from the antenna 116 receive. According to an exemplary embodiment of the present invention, the RF input signal x (t) may be from an amplifier 402 be amplified before it to the coarse-sensing module 104 is delivered. For example, the amplifier 402 an amplifier pre-stage that can serve to provide uniform amplification over a wide frequency range.
  • With reference to the coarse-sensing module 104 out 4A can the coarse-sensing module 104 an analog wavelet waveform generator 404 , an analog multiplier 406 , an analog integrator 408 and a time clock 410 exhibit. The time clock 410 can be time signals generated by the wavelet generator 404 and the analog integrator 408 be used to deliver. Analog correlation values may be present at the output of the analog integrator 408 be provided, which in turn to an analog-to-digital converter (ADC) 118 which may have a low speed according to an exemplary embodiment of the present invention. The digitized correlation values at the output of the ADC 118 can be sent to the MAC (Medium Access Control) module 124 to be delivered.
  • Further referring to 4A can the wavelet generator 404 of the coarse-sensing module 104 to generate a string of wavelet pulses v (t) which are modulated to form a string of modulated wavelet pulses w (t). For example, the string of wavelet pulses v (t) may be modulated with sinusoidal I and Q carriers f LO (t) at a given local oscillator (LO) frequency. With the sinusoidal I and Q carriers f LO (t), the signal of the I component may be the same size as the signal of the Q component but 90 degrees out of phase. The chain of modulated wavelet pulses w (t) obtained by the wavelet generator 404 has been output, can then with the time-variant input signal x (t) by the analog multiplier 406 multiplied or otherwise linked to form an analogue correlation output signal z (t) which is fed to the analogue integrator 408 is entered. The analog integrator 408 determines the analog correlation values y (t) and outputs them.
  • The analog correlation values y (t) are at the output of the analog integrator 408 associated with the wavelet pulses v (t) having a given spectral width based on the pulse width and resolution bandwidth described above. Referring again to the coarse-sensing module 104 out 4A the wavelet pulse v (t) is modulated using the sinusoidal I and Q carriers f LO (t) to form the modulated wavelet pulses w (t). The local oscillator (LO) frequency of the sinusoidal I and Q carriers f LO (t) can then be swept or adjusted. By sweeping the sinusoidal I and Q carriers f LO (t), the signal power quantity and the frequency values in the time-variant input signal x (t) can be detected in the analog correlation values y (t) over a range of the spectrum, and especially over the range of the spectrum of interest, providing a scalable resolution.
  • For example, by applying a narrow wavelet pulse v (t) and a large tuning step size of the LO frequency f LO (t) with an MRSS implementation according to an embodiment of the present invention, a very wide range of the spectrum can be studied quickly and efficiently become. In contrast, a very accurate scanning of the spectrum can be performed with a wide wavelet pulse v (t) and the fine adjustment of the LO frequency f LO (t). Further, according to an exemplary embodiment of the present invention, passive filters for image rejection due to the bandpass filtering effect of the window signal (eg, modulated wavelet pulses w (t)) may not be required for this MRSS implementation. Likewise, the hardware overhead, including high power consuming digital hardware overhead, of such MRSS implementation can be minimized. In 4B For example, one example of such a scalable resolution control in the frequency domain is shown using wavelet pulses W (ω). In particular, in 4B illustrated that an input signal W (ω) multiplied by wavelet pulses W (ω) with varying resolution bandwidths 406 to obtain a scalable resolution control of the various output correlation values Y (ω).
  • Referring again to 4A can, once the analog correlation values y (t) from the analog integrator 408 were generated, the magnitudes of the coefficient values from the analog-to-digital converter 118 digitized and sent to the MAC module 124 to be delivered. Specifically, the resulting analog correlation values y (t) associated with each of the I and Q components of the wavelet waveforms may be obtained from the analog to digital converter 118 be digitized, and their size will be determined by the MAC module 124 recorded. If the values are greater than a certain threshold level, the sensing scheme becomes, for example, using the spectrum detection module 120 in the MAC module 124 , determine a significant interference originator reception (eg, a particular detected spectrum occupancy) in accordance with an embodiment of the present invention.
  • c. Simulation of an MRSS implementation
  • An MRSS implementation according to an embodiment of the present invention will now be described in more detail with respect to several computer simulations. In particular, a computer simulation was performed using a dual tone signal x (t), where each tone was set at the same amplitude but at a different frequency. The sum of the double tone signals with different frequencies and the phases can be expressed as x (t) = A 1 cos (ω 1 t + θ 1 ) + A 2 cos (ω 2 t + θ 2 ). In 5A the waveform of the double tone signal x (t) is shown, and in 5B FIG. 3 illustrates the corresponding spectrum to be detected with the MRSS implementation according to an embodiment of the present invention.
  • In accordance with the exemplary simulated MRSS implementation, the Hanning window function (ie, Wt * Wf = 0.513) for this exemplary simulated MRSS implementation has been chosen as a wavelet window function that selects the wavelet pulse width Wt and the resolution bandwidth Wf for the wavelet pulses v (t) conditionally. The Hanning window function was used in this simulation because of its relative simplicity in terms of practical implementation. The uncertainty inequality Wt · Wf = 0.513 as described above can be derived from the calculations of the wavelet pulse width (wt) 302 and the resolution bandwidth (Wf) 304 for the Hanning wavelet pulses as shown below:
    Figure 00200001
  • In 6 2, the waveform of the exemplary string of wavelet pulses v (t) is shown. Accordingly, a string of modulated wavelet pulses w (t) from the wavelet generator 404 by modulating the sinusoidal I and Q carriers f LO (t) with a window signal consisting of a string of wavelet pulses v (t), in an exemplary embodiment of the present invention. In particular, the modulated wavelet pulses w (t) can be obtained by w (t) = v (t) * f LO (t) if v (t) = 1 + m cos (ω p t + θ p ) and
    Figure 00200002
    Φ = 0 or 90 °. In 7A the I component of the waveform of the sinusoidal IQ carrier f LO (t) is shown, and in 7B the Q component of the waveform of the sinusoidal IQ carrier f LO (t) is shown. In 8A are the modulated wavelet pulses w (t) produced by the wavelet generator 404 obtained with the I-component of the IQ sinusoidal carrier f LO (t), is shown. Similarly, in 8B the modulated wavelet pulses w (t) generated by the wavelet generator 404 with the Q component of the sinusoidal IQ carrier f LO (t) are shown.
  • Each modulated wavelet pulse w (t) is then compared with the time-variant signal x (t) by means of an analog multiplier 406 multiplied to produce the resulting analog correlation output signals z (t) as in 9A and 9B is shown. In particular, in 9A the correlation output signal z (t) waveform for the input signal x (t) is represented with the I component of the sinusoidal IQ carrier f LO (t), whereas in 9B the correlation output signal z (t) waveform for the input signal x (t) is shown with the Q component of the sinusoidal IQ carrier f LO (t). The resulting, in 9A and 9B displayed waveforms are then by means of the analog integrator 408 integrated to obtain the correlation values y (t) of the input signal x (t) with the I and Q components of the wavelet waveform w (t).
  • The correlation values y (t) can then be determined by means of the analog integrator 408 be integrated and from the analog-to-digital converter 118 be scanned. 10A shows the sampled values y I , that of the analog-to-digital converter 118 for these correlation values y (t) with the I component of the wavelet waveform w (t) in the given interval. 10B shows the means of the analog integrator 408 and the analog-to-digital converter 118 for the correlation values of the Q component of the wavelet waveform w (t) in the given interval sampled values y Q. The MAC module 124 , and optionally its constituent spectrum detection module 120 then, according to an embodiment of the present invention, calculates the size of the sampled values by taking the square root of the values y I and Y Q , as by
    Figure 00210001
    shown. The from the spectrum detection module 120 in the MAC module 124 detected form of the spectrum is in 11 shown. As in 11 shown, the detected shape of the spectrum fits well with the in 5B represented expected spectrum, resulting in good detection and detection of the expected Spek clarified.
  • 12 - 17 illustrate simulations of various signal formats detected using exemplary MRSS implementations in accordance with embodiments of the present invention. These signal formats may include GSM, EDGE, Wireless Microphone (FM), ATDC (VSB), 3G cellular WCDMA, IEEE802.11a WLAN (OFDM). In particular, in 12A the spectrum of the GSM signal is shown and in 12B the corresponding detected signal spectrum. Similarly, in 13A represented the spectrum of an EDGE signal and in 13B the corresponding detected signal spectrum. In 14A is the spectrum of a signal of a wireless microphone (FM) shown in and 14B the corresponding detected signal spectrum. In 15A is the spectrum of an ATDC (VSB) signal represented and in 15B the corresponding detected signal spectrum. In 16A the spectrum of a cellular 3G WCDMA signal is shown and in 16B the corresponding detected signal spectrum. In 17A the spectrum of an IEEE 802.11a WLAN (OFDM) signal is shown and in 17B the corresponding detected signal spectrum. Those skilled in the art will recognize that other signal formats may be detected in accordance with MRSS implementations in accordance with embodiments of the present invention.
  • d. Circuit diagram for one Coarse Abfühlblock
  • An exemplary circuit diagram for a coarse-sensing module 104 represented in 4 , is in 18 shown. More precisely in 18 a wavelet generator 454 , Multipliers 456a and 456b as well as integrators 458a and 458b shown. The wavelet generator 454 can be from a wavelet pulse generator 460 , a local oscillator (LO) 462 , a phase shifter 464 (eg a 90 ° phase shifter) and multipliers 466a and 466b consist. The wavelet pulse generator 460 may provide sheath signals that determine the width and / or shape of the wavelet pulses v (t). Using the multiplier 466a is the wavelet pulse v (t) with the I component of the LO 462 multiplied by the delivered LO frequency to produce the I-component modulated wavelet pulse w (t). Likewise, using the multiplier 466b the wavelet pulse v (t) with the Q component of the LO frequency as from the phase shifter 464 shifted by 90 °, multiplied to produce the modulated with the Q component wavelet pulse w (t).
  • The respective I and Q components of the modulated wavelet pulses w (t) are then multiplied by the corresponding multipliers 456a and 456b multiplied to produce the respective correlation output signals z I (t) and z Q (t). The correlation outputs z I (t) and z Q (t) are then provided by the respective integrators 458a and 458b integrated to give the respective correlation values y I (t) and y Q (t). Although in 18 a specific embodiment is illustrated, the person skilled in the art will recognize that many changes in the circuit diagram 18 possible are.
  • 2. Fine-sensing module
  • According to an exemplary embodiment of the present invention, the fine-sensing module 106 out 1 serve to detect periodic features of the input signals that are unique to each suspect modulation format or frame structure. The periodic features may include sinusoidal carriers, periodic pulse trains, cyclic prefixes, and preambles. In particular, the fine-sensing module 106 implement one or more correlation functions to detect these periodic features of the input signals. The detected input signals can include a variety of advanced signal formats used in current and emerging wireless standards, including IS-95, WCDMA, EDGE, GSM, Wi-Fi, Wi-Max, Zigbee, Bluetooth, digital television (ATSC, DVB) and Similar, to be used.
  • In accordance with one embodiment of the present invention, that for the fine-sensing module 106 implemented correlation function be an analog auto-correlation function (AAC = Analog Auto Correlation). The AAC function can derive the degree of agreement (ie, correlation) between two signals. In other words, the correlation between the same waveforms produces the highest value. However, since the data of the modulated waveform has a random feature because the underlying original data contains random values, the correlation between the periodic signal waveform and the modulated signal waveform data can be ignored. Instead, the periodic characteristic of a given signal (eg, modulation format or frame structure) has a high correlation that can be used by the AAC function as a signature for the specific type of signal. The of the AAC function in the fine-sensing module 106 identified specific signal type can be sent to the signal processing module 126 to reduce interference effects.
  • a. Block diagram of a AAC implementation
  • In 19 Fig. 10 is a functional block diagram of an exemplary fine-sensing module 106 using the AAC function according to one embodiment of the present invention. In particular, the fine-sensing module 106 an analog delay module 502 , an analog multiplier 504 , an analog integrator 506 and a comparator 508 exhibit. The at the output of the fine-sensing module 106 provided analog correlation values can be from an analog-to-digital converter 118 be digitized, which may have a low speed according to an embodiment of the present invention.
  • With reference to the fine-sensing module 106 out 19 becomes an RF input signal x (t) from the antenna 116 from the analog delay module 502 delayed by a certain delay value T d . The one from the analog delay block 502 supplied delay value T d may be a predetermined and unique value for each periodic signal format. For example, an IEEE 802.11a WLAN (OFDM) signal may be associated with a first delay value T d1 , whereas a 3G cellular (WCDMA) signal may be associated with a second delay value T d2 that is different from the first delay signal T d1 .
  • The analogous correlation between the original input signal x (t) and the corresponding delayed signal x (t-T d ) can be obtained by multiplying or otherwise linking these two signals - the original input signal x (t) and the delayed signal x (t - T d ) - with an analog multiplier 504 be performed to form a correlation signal. The correlation signal is then provided with an analog integrator 506 integrated to give correlation values. The analog integrator 506 may be a sliding window integrator according to an exemplary embodiment of the present invention. If correlation values from the integrator 506 are greater than a certain threshold as from the comparator 508 determined, the signal type specific to the original input signal from the spectrum detection module 120 of the MAC module 124 be identified. According to an embodiment of the present invention, the threshold value may be predetermined for each type of signal. These types of signals may include IS-95, WCDMA, EDGE, GSM, Wi-Fi, Wi-Max, Zigbee, Bluetooth, digital television (ATSC, DVB), and the like.
  • As the example AAC implementation out 19 All signals processed in the analog domain, this not only allows real-time operation, but also low power consumption. By applying a delay T d and thus correlating to the input signal, blind detection can be achieved without the need for known reference signals. This blind detection can dramatically reduce hardware overhead and / or power consumption for reference signal recovery. Furthermore, according to an embodiment of the present invention, the AAC implementation may include 19 increase the spectrum sensing performance once provided in connection with an MRSS implementation as described above. In particular, if the MRSS implementation has detected receipt of a suspected interference-causing signal, the AAC implementation may examine the signal and recognize its specific type of signal based on the signature.
  • b. Simulation of an AAC implementation
  • According to an embodiment of the present invention, the AAC implementation may include 19 be simulated for a variety of signal types. As an example, an IEEE 802.11a OFDM (Orthogonal Frequency Division Multiplexing) signal may always have synchronization preambles at the beginning of a frame structure. For the sake of simplicity, only an exemplary OFDM data symbol will be used 552 from an exemplary preamble 551 as in 20A shown followed. 20B FIG. 12 shows the spectrum of the IEEE802.11a input signal to be detected with an AAC implementation according to one embodiment of the present invention. FIG.
  • 21A represents the IEEE802.11a input signal x (t) and 21B the delayed IEEE802.11a signal x (t - T d ). In 22 For example, a waveform of a correlation between the original input signal x (t) and the delayed signal x (t-T d ) is shown as at the output of the multiplier 504 provided. The resulting in 22 Waveform shown may be for preambles 551 consecutive positive values 554 exhibit. The result of the integrator 506 , as in 23 can be represented for the digits of the preamble 551 in the IEEE802.11a frame structure peaks 602 . 604 exhibit. However, the correlation points to the modulated data symbols 552 random values 556 which, after integration by the analog integrator 506 can be ignored. By comparing the predetermined thresholds Vth using a comparator 508 with the resulting in 23 The illustrated waveform may include the example AAC implementation 19 determine the reception of the IEEE 802.11a OFDM signal.
  • Numerous changes made with respect to 19 described AAC implementation are possible. In an alternative embodiment, the output may be from the integrator 506 by means of the analog-to-digital converter 118 be digitized before a comparison with the threshold Vth from the comparator 508 is carried out. Although in one embodiment, the coarse-sensing module 104 and the fine-sensing module 106 the analog-to-digital converter 118 In other embodiments, for both the coarse-sensing module 104 as well as for the fine-sensing module 106 in each case a separate analog-to-digital converter can be provided. Similarly, the multiplier 504 and the integrator 506 of the fine-sensing module 106 equal or different to the multiplier 406 and the integrator 408 of the coarse-sensing module 104 be. Numerous other changes will be known to those skilled in the art.
  • C. Signal processing block
  • Referring again to 1 becomes a signal processing module 126 which, according to an exemplary embodiment of the present invention, may be a block of the physical layer. The signal processing module 126 may provide baseband processing, including one or more modulation and demodulation schemes. Furthermore, the signal processing module 126 also provide interference attenuation, optionally based on any identified interference-cause signals. Furthermore, the signal processing module 126 serve to reconfigure the radio front end, including the transmitter 110 and / or recipient 112 at least partially based on the available spectrum. For example, the signal processing block may control the transmission power control of the transmitter 110 customize or a filter of the receiver 112 to operate in a certain frequency range. One of ordinary skill in the art will readily recognize that other baseband processing by the signal processing module 126 as may be required or desirable.
  • D. Frequency Agile Wireless Frontend
  • 24 FIG. 10 illustrates an example configuration of a frequency agile radio front end. FIG 108 According to an embodiment of the present invention. In particular, the reception range of the radio front end 108 one or more tunable filters 702 , a broadband receiver 704 and one or more low-pass filters 706 exhibit. The tunable filter 702 may comprise a wavelet generator and a multiplier according to an exemplary embodiment of the present invention. The broadband receiver 704 may have one or more frequency levels and one or more downconverters as required. Furthermore, the transmission range of the radio frontend 108 one or more low pass filters 708 , a broadband station 710 and one or more power amplifiers 712 exhibit. The broadband transmitter 710 may also have one or more frequency levels and one or more boosters as required. Furthermore, the broadband receiver 704 and the transmitter 710 in conjunction with a tunable signal generator 714 be. One of ordinary skill in the art will recognize that components of the frequency agile radio frontend 108 can be changed without departing from the embodiments of the present invention.
  • As previously with reference to 1 and 2 specified, processes the MAC module 124 the digitized data (eg by means of the ADC 118 ) from the spectrum recognition module 102 to provide an available spectrum for a secure (ie unassigned or non-interfering) cognitive radio link 100 to locate. Furthermore, the MAC module delivers 108 the reconfiguration control signal for the optimal radio link in the assigned frequencies to the radio front end 108 , Then the wireless frontend changes 108 the RF operating frequency in the corresponding frequency value according to its frequency-agile operation. In particular, either the tunable filter 702 or the tunable signal generator 714 or both change their operating frequency to select the signals in the corresponding frequency range. Meanwhile, based on the control information of the MAC module 124 , the PHY signal processing module 126 improve the connection performance through the adaptive modulation and interference mitigation technique.
  • Numerous modifications and other embodiments of the invention described herein will become apparent to those of ordinary skill in the art to which the invention belongs, which benefit from the teachings disclosed in the foregoing description and accompanying drawings. Consequently It should be understood that the invention is not limited to the particular embodiments disclosed, and that modifications and other embodiments are within the scope of the appended claims. Although certain terms are used herein, they are used in a generic and descriptive sense only and are not intended to be limiting.

Claims (20)

  1. Radio frequency (RF) spectrum sensing system, which has: a multiplier, which is an RF input signal and a delayed one RF input signal connected, to generate a correlation signal; an integrator that receives the correlation signal from the multiplier, wherein the integrator by integrating the correlation signal correlation values certainly; and a comparator in conjunction with the integrator, which correlates with one or more thresholds compares to generate information that is at least one signal feature of the RF input signal.
  2. System according to claim 1, characterized in that the at least one signal feature Modulation and / or frame structure of the RF input signal has.
  3. System according to claim 1, characterized in that a delay of the delayed RF input signal is reconfigurable.
  4. System according to claim 1, characterized in that the integrator with an integrator is sliding window.
  5. System according to claim 1, characterized in that the system further comprises an analog-to-digital converter for digitizing the correlation values.
  6. System according to claim 1, characterized in that a value for one or more of the thresholds is reconfigurable.
  7. System according to claim 1, characterized in that the multiplier the correlation signal by Multiplying the RF input signal with the delayed RF input signal generated.
  8. Method for identifying the use of a radio-frequency (RF) spectrum, comprising: Receiving an RF input signal; Delaying the RF input signal to a delayed RF input signal to create; Link of the RF input signal with the delayed RF input signal to obtain a correlation signal to create; Calculate correlation values by integrating the correlation signal; and Compare the correlation values with at least one threshold to generate information indicate the at least one signal feature of the RF input signal.
  9. Method according to claim 8, characterized in that the comparison of the correlation values Comparing the correlation values with at least one threshold includes to generate information, the modulation type and / or Frame structure of the RF input signal Show.
  10. Method according to claim 8, characterized in that it reconfigures a delay in Connection with the delayed RF input signal includes.
  11. Method according to claim 8, characterized in that the calculation of the correlation values is the Calculate the correlation values by applying an integrator with sliding window on the correlation signal.
  12. Method according to claim 8, characterized in that it is the digitizing of the information, which indicates at least one signal feature of the RF input signal.
  13. Method according to claim 8, characterized in that it is the reconfiguring of a value for at least includes a threshold.
  14. Method according to claim 8, characterized in that the linking of the RF input signal and of the delayed RF input signal multiplying the RF input signal by the delayed RF input signal includes.
  15. A radio frequency (RF) spectrum sensing device comprising: a Antenna for receiving an RF input signal; a delay module, which delays the RF input signal to a delayed RF input signal to create; a multiplier for combining the RF input signal with the delayed RF input signal to generate a correlation signal; one Integrator that integrates the correlation signal to correlation values to calculate; and a comparator that determines the correlation values with at least one threshold compares to information to generate on at least one signal feature of the input radio signal clues.
  16. Device according to claim 15, characterized in that the delay of the delay module is reconfigurable.
  17. Device according to claim 15, characterized in that the integrator integrator with is sliding window.
  18. Device according to claim 15, characterized in that a value for at least one threshold is reconfigurable.
  19. Device according to claim 15, characterized in that the at least one signal feature the Modulation type and / or the frame structure of the RF input signal having.
  20. Device according to claim 15, characterized in that the multiplier serves to the RF input signal with the delayed RF input signal to multiply.
DE102006048542A 2005-10-21 2006-10-13 Systems, methods and devices for fine-sensing modules Ceased DE102006048542A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US72903405P true 2005-10-21 2005-10-21
US60/729,034 2005-10-21
US11/458,280 2006-07-18
US11/458,280 US20070092045A1 (en) 2005-10-21 2006-07-18 Systems, Methods, and Apparatuses for Fine-Sensing Modules

Publications (1)

Publication Number Publication Date
DE102006048542A1 true DE102006048542A1 (en) 2007-05-31

Family

ID=37232271

Family Applications (1)

Application Number Title Priority Date Filing Date
DE102006048542A Ceased DE102006048542A1 (en) 2005-10-21 2006-10-13 Systems, methods and devices for fine-sensing modules

Country Status (6)

Country Link
US (1) US20070092045A1 (en)
KR (1) KR100780178B1 (en)
DE (1) DE102006048542A1 (en)
FI (1) FI20065665A (en)
FR (1) FR2892578B1 (en)
GB (1) GB2431550A (en)

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2893202A1 (en) * 2005-11-07 2007-05-11 France Telecom Method and system for occupancy and transmission spectrum allocation
US7528751B2 (en) 2006-07-28 2009-05-05 Samsung Electro-Mechanics Systems, methods, and apparatuses for a long delay generation technique for spectrum-sensing of cognitive radios
US7831414B2 (en) * 2006-10-06 2010-11-09 Qualcomm Incorporated Method and apparatus for detecting a presence of a signal in a communication channel
US7768252B2 (en) * 2007-03-01 2010-08-03 Samsung Electro-Mechanics Systems and methods for determining sensing thresholds of a multi-resolution spectrum sensing (MRSS) technique for cognitive radio (CR) systems
KR101298326B1 (en) * 2007-05-07 2013-08-20 엘지전자 주식회사 Apparatus for Detecting Spectrum using Time Delay
US7933368B2 (en) * 2007-06-04 2011-04-26 Ibiquity Digital Corporation Method and apparatus for implementing a digital signal quality metric
US7933367B2 (en) * 2007-06-04 2011-04-26 Ibiquity Digital Corporation Method and apparatus for implementing seek and scan functions for an FM digital radio signal
US20080309829A1 (en) * 2007-06-14 2008-12-18 Koninklijke Philips Electronics, N.V. Frequency selective radio sensor and a method thereof
US8184656B2 (en) * 2007-10-02 2012-05-22 Microsoft Corporation Control channel negotiated intermittent wireless communication
CN102047749B (en) * 2008-05-27 2014-07-02 日本电气株式会社 Cognitive wireless system, cognitive wireless device, and wireless signal detection method
JP5260250B2 (en) 2008-12-08 2013-08-14 株式会社トヨタIt開発センター Unused frequency band detection method and radio communication apparatus in cognitive radio system
KR101104875B1 (en) * 2009-08-05 2012-01-17 한국수력원자력 주식회사 Method and computer-readable recording medium for measuring rod drop time
KR101584846B1 (en) 2009-12-21 2016-01-25 톰슨 라이센싱 Autocorrelation-based spectrum sensing for fm signals
EP2754246B1 (en) 2011-09-09 2016-06-22 Per Vices Corporation Systems and methods for performing demodulation and modulation on software defined radios
CA2835035A1 (en) * 2011-05-06 2012-11-15 Per Vices Corporation System and method for decoding a radio signal
IL228776D0 (en) * 2013-10-08 2014-03-31 Rabinovich Roman Analog -to-inforamation converter via spectrum-compression
US9755869B2 (en) * 2013-11-18 2017-09-05 Bae Systems Information And Electronic Systems Integration Inc. Process for tunnelized cyclostationary to achieve low-energy spectrum sensing
US9860848B2 (en) 2016-05-31 2018-01-02 Apple Inc. Baseband power estimation and feedback mechanism

Family Cites Families (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1187944A (en) * 1982-09-15 1985-05-28 Her Majesty The Queen, In Right Of Canada, As Represented By The Ministe R Of National Defence Spectrum surveillance receiver system
US4815137A (en) * 1986-11-06 1989-03-21 American Telephone And Telegraph Company Voiceband signal classification
US5282227A (en) * 1992-05-21 1994-01-25 The Titan Corporation Communication signal detection and acquisition
DE4242908B4 (en) * 1992-12-18 2006-04-20 Eads Deutschland Gmbh Method for detecting the modulation types A3E, J3E and F3E and arrangement for carrying out the method
US5386495A (en) * 1993-02-01 1995-01-31 Motorola, Inc. Method and apparatus for determining the signal quality of a digital signal
US5532699A (en) * 1994-09-19 1996-07-02 E-Systems, Inc. Non-coherent radar system having improved resolution capabilities
US5638399A (en) * 1994-11-15 1997-06-10 Stanford Telecommunications, Inc. Multi-beam satellite communication system with user terminal frequencies having transceivers using the same set of frequency hopping
US5974042A (en) * 1997-02-28 1999-10-26 Motorola, Inc. Service detection circuit and method
US7280607B2 (en) * 1997-12-12 2007-10-09 Freescale Semiconductor, Inc. Ultra wide bandwidth communications method and system
US6928046B1 (en) * 1999-05-05 2005-08-09 Lucent Technologies Inc. Frame synchronization of an OFDM signal
US7394866B2 (en) * 2000-10-10 2008-07-01 Freescale Semiconductor, Inc. Ultra wideband communication system, method, and device with low noise pulse formation
US20020065047A1 (en) * 2000-11-30 2002-05-30 Moose Paul H. Synchronization, channel estimation and pilot tone tracking system
JP2003018116A (en) * 2001-06-29 2003-01-17 Sony Corp Frequency-offset detecting circuit and demodulator
EP1282257A1 (en) * 2001-08-02 2003-02-05 Mitsubishi Electric Information Technology Centre Europe B.V. Method and apparatus for detecting data sequences
US6781446B2 (en) * 2001-10-19 2004-08-24 Harris Corporation Method and apparatus for the detection and classification of signals utilizing known repeated training sequences
US7099422B2 (en) * 2002-04-19 2006-08-29 General Electric Company Synchronization of ultra-wideband communications using a transmitted-reference preamble
US7116943B2 (en) * 2002-04-22 2006-10-03 Cognio, Inc. System and method for classifying signals occuring in a frequency band
CN100566316C (en) * 2003-07-11 2009-12-02 Nxp股份有限公司 Method and apparatus for coarse and fine frequency and timing synchronisation
US7181187B2 (en) * 2004-01-15 2007-02-20 Broadcom Corporation RF transmitter having improved out of band attenuation
JP2005351237A (en) * 2004-06-14 2005-12-22 Toyota Motor Corp Failure detection device and failure detection method for start switch of power device
US20060221918A1 (en) * 2005-04-01 2006-10-05 Hitachi, Ltd. System, method and computer program product for providing content to a remote device

Also Published As

Publication number Publication date
FI20065665A (en) 2007-04-22
FR2892578B1 (en) 2012-11-23
GB0620956D0 (en) 2006-11-29
FR2892578A1 (en) 2007-04-27
FI20065665D0 (en)
GB2431550A (en) 2007-04-25
US20070092045A1 (en) 2007-04-26
KR20070043602A (en) 2007-04-25
KR100780178B1 (en) 2007-11-27
FI20065665A0 (en) 2006-10-18

Similar Documents

Publication Publication Date Title
Bhargavi et al. Performance comparison of energy, matched-filter and cyclostationarity-based spectrum sensing
Yang et al. Ultra-wideband communications: an idea whose time has come
Mishali et al. Wideband spectrum sensing at sub-Nyquist rates [applications corner]
JP4808888B2 (en) Correction of sampling frequency offset in orthogonal frequency division multiplexing system
US10461802B2 (en) Method and apparatus for an adaptive filter architecture
KR100673084B1 (en) Radio communication system employing spectral reuse transceivers
JP4309878B2 (en) Wireless terminal
US5677927A (en) Ultrawide-band communication system and method
EP1941620B1 (en) Apparatus and method for interference mitigation
Tang Some physical layer issues of wide-band cognitive radio systems
US8077676B2 (en) System and method for wireless channel sensing
EP0847643B1 (en) Method for simplifying the demodulation in multiple carrier transmission system
Sharma et al. Application of compressive sensing in cognitive radio communications: A survey
JP2008535358A (en) Signal receiver for broadband wireless communication
US6980613B2 (en) Ultra-wideband correlating receiver
Da Silva et al. Distributed spectrum sensing for cognitive radio systems
Farhang-Boroujeny et al. Multicarrier communication techniques for spectrum sensing and communication in cognitive radios
CN101155423B (en) Spectrum sensing algorithm and method
US7363008B2 (en) Spectrum sharing in the unlicensed band
JP2006121546A (en) Radio communication equipment
EP1702445B1 (en) Modulation and demodulation of ofdm signals
EP1537679B1 (en) Sub-banded ultra-wideband communication system
US7965982B2 (en) Reconfigurable wireless communications device and radio
CN1697438A (en) Preamble generator for a multiband OFDM transceiver
Park et al. A fully integrated UHF-band CMOS receiver with multi-resolution spectrum sensing (MRSS) functionality for IEEE 802.22 cognitive radio applications

Legal Events

Date Code Title Description
OP8 Request for examination as to paragraph 44 patent law
8128 New person/name/address of the agent

Representative=s name: LINDNER BLAUMEIER PATENT- UND RECHTSANWAELTE, 9040

R002 Refusal decision in examination/registration proceedings
R003 Refusal decision now final

Effective date: 20130301